Electric vacuum horn



H T A E H c H ELECTRIC VACUUM HORN Filed July 18, 1932 A TTORNE YS.

Patented May 26, 1936 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to signal horns as used principally for automobiles and the objects of the invention are to provide improvements whereby a combination of electric and vacuum or air operated horn is effected which will have unusual power. Other features and advantages of the invention will appear in the following description and accompanying drawings.

In the drawing Fig. 1 is a central cross section of the apparatus taken through the sound box chamber, diaphragm and spiral horn chamber.

Fig. 2 is a plan View of half of the spiral horn as seen from the line 2-2 of Fig. 1.

Before describing the invention in detail, it may be said that as the invention comprises coupling up an electrically vibrated diaphragm type of horn with the vacuum or air pulsating horn principally, neither half need be of any new design as there are existing designs perfectly 20 suitable for the purpose when coupled in conformity with the invention and in the drawing I show a conventional electrical diaphragm operating mechanism in which the vibrating diaphragm itself carries an armature and a trip which breaks the circuit each time the diaphragm is flexed toward the magnet, and the vacuum or air impulse side .of the apparatus is very much like that shown in the disclosure of my U. S. Patent #1,865,006 and no claim is made to the separate construction broadly of these two essential halves of the device.

In the drawing I is the diaphragm, here shown as a corrugated sheet metal disk peripherally supported in fiat rings 2 faced with gaskets 3 35 and clamped as by screws l6 between the concave rear wall 4 and front wall 5 of the sound box chamber.

The diaphragm carries on one side a relatively heavy iron disk armature 6 adapted to be drawn toward the poles l, 8 of a cup-shaped electromagnet, when the winding 9 is energized, by closing of a remote switch on the circuit not shown, and upon which event a pin it projecting from the armature will force inward a resilient trip arm II to thus break the contacts l2 in series with the magnet, to thus de-energize the magnet and permit the diaphragm to spring back to starting position. So far this part of the device is of known construction.

The front wall 5 of. the sound box lies on the opposite side of the diaphragm and has formed on its outer side one-half of a spiral horn chamber I3, the other half. I3 of which is formed in a third body member l4 clamped in place as by screws 15. The spiral horn passage or resonating chamber gets larger in an outward direction to terminate in a socket ll in which is secured a sleeve l8 threaded on its projecting end and to which is screwed a sheet metal trumpet IQ of any size desired. A pipe connection extends through member 5 and opens into the sound box chamber. This pipe is adapted for connecting to the inhaust manifold of an automobile engine, or to any other source of vacuum or to a source of air pressure. Attached to the outer side of the diaphragm is a concave reinforcing washer 2|.

The air horn portion so far described is also of known construction, but the relation of the two portions, as well as the further details, are not of known construction.

Washer 2| has several holes 22, formed in it, and several holes 23 are also formed in the diaphragm near the center of the same so as to insure a balanced air pressure on both sides of. the diaphragm, and mounted upon the outer arched side of washer 2! is a small washer 24 on top of which is a thin resilient spring bronze disk 25 against which lies a disk 26 of bakelite or other non-metallic material. It is a necessary function of disk 25 that it be resilient and more yielding than the main diaphragm l and to aid in this it may be cupped instead of flat if desired. This assemblage mounted on the diaphragm is held in place by a rivet or screw 21 passing through the diaphragm and into the armature as indicated.

Disk 26 is in reality an air valve and its function is to close the horn opening by seating against the rim of a funnel-like member 28 screwing back and forth on a short threaded neck 29 formed at the central terminus of the spiral horn chamber. Member 28 is provided with spur gear teeth 30 just outside of its threaded portion and which teeth are engaged by a small spur gear 3| having a shank 32 extending rotatably through both sections of the spiral horn body and accessible at the outer side of the horn body member [4 where it is slotted as at 32 for a screw-driver and provided with a screw lock nut 33 for clamping in any position of turning.

Upon turning the spur gear shank 32 the funnel or cup 28 is moved in an axial direction to bear with any desired degree of force against the air valve disk 25 to normally close the same against in or out air to thehorn.

A thick disk of soft, compressible rubber 35 around the neck 29 and between the upper end of cup 28 where threaded on neck 29 and the body of the spiral horn chamber insures an air-tight joint while permitting adjustment of the cup 28. A thin, metallic disc 35 is between the disc and cup 28 to permit the cup to be turned easily while the rubber is under compression.

It is of course evident that other forms of air valve may be used at this place of the construction, if desired, without affecting the mode of operation of the invention.

In operation, upon closing the electrical circuit the diaphragm is drawn toward the magnet, the circuit is broken and the diaphragm springs back in rapid succession, depending on the stiffness of the diaphragm as well as the tension and adjustment of the breaker contact by means of screw 34. However, the moment the diaphragm moves toward the magnet it also opens the air valve a trifie so that an air suction or blast impulse passes therethrough, and when the position of the funnel valve or its pressure upon the resilient valve disk is properly adjusted a rhythmic relation between the two sources of motive power is established which builds up a note of totally unprecedented carrying power, though not a raucous note. This compound action is of course only available when the engine of the automobile is running, unless an air or vacuum tank is carried, but when the engine is not running the horn will still operate as an electric horn of remarkable intensity, as it seems that the rapid, sharp cutting off of the horn passage by the valve greatly increases the carrying quality of the sounds produced. Another fact of importance to be noted is that a vacuum operates with much greater intensity than when air pressure is used.

Normally the adjustment of the funnel pressure against the resilient valve disk is such as to keep the passage closed, so that the additional force of the electro-magnet pulling against the armature is required to open it.

It is of course evident that the spiral horn chamber may be disposed with and a straight horn alone used, but the arrangement shown is compact and of startling effectiveness.

I find a much better note is secured by mounting the horn by means of a bracket 36 clamped between a pair of soft rubber blocks 31 on the frame 38 or other support.

Having thus described my invention what I claim is:

1. A signal horn comprising a diaphragm mounted within a chamber, an inwardly opening valve disk normally closing the opening from the chamber to said horn and connected to said diaphragm for simultaneous operation therewith, a horn opening out from the chamber, electrically operated means for vibrating said diaphragm, and vacuum creating means connected to said chamber arranged for causing a suction impulse through said horn upon vibration of the diaphragm, said diaphragm being perforated for balancing the pressure between its opposite sides.

2. In a signal horn, a casing providing an enclosed chamber, a diaphragm mounted within said casing dividing the chamber into two compartments, electro-magnetic means positioned within one of said compartments arranged and adapted to vibrate the diaphragm upon the electro-magnetic means being energized, an air passage opening from said chamber, a valve connected to said diaphragm arranged and adapted to intermittently open and close said air passage upon the diaphragm being vibrated, suction creating means connected to said chamber, and means providing for free communication of air between said compartments.

3. In a signal horn, a casing providing an enclosed chamber, a diaphragm mounted within said casing dividing the chamber into separate enclosed compartments, electro-magnetic means in one of said compartments arranged and adapted to vibrate the diaphragm upon the electro-magnetic means being energized, an air passage opening out from said chamber, a valve connected to said diaphragm arranged and adapted to intermittently open and close said air passage upon the diaphragm being vibrated, suction creating means connected to said chamber, said diaphragm being provided with an opening for permitting air communication between the said compartments.

HARRY C. HEATH. 

